added several grid-walks

added new helper methods/classes (e.g. for heading)
new test cases
optimize the dijkstra
cleanups/refactoring
added timed-benchmarks to the log
many more...

grid/GridPoint.h

@@ -4,6 +4,8 @@
 #include <cmath>
 #include "../geo/Point3.h"
 
+#include <KLib/Assertions.h>
+
 struct GridPoint {
 
 	/** x-position (in centimeter) */
@@ -42,6 +44,13 @@ struct GridPoint {
 	/** cast to string */
 	operator std::string() const {return "(" + std::to_string(x_cm) + "," + std::to_string(y_cm) + "," + std::to_string(z_cm) + ")";}
 
+	/** read-only array access */
+	float operator [] (const int idx) const {
+		_assertBetween(idx, 0, 2, "index out of bounds");
+		if (0 == idx)	{return x_cm;}
+		if (1 == idx)	{return y_cm;}
+						{return z_cm;}
+	}
 
 };